The present disclosure diagnoses and informs of insufficiency of a coolant through a cooperative control between controllers, without using a separate sensor in a hybrid vehicle, or the like, in which an electric water pump (EWP) is mounted.
In the hybrid vehicle, or the like, temperature is an important factor in normal operation of a power converter component. Excessive heat causing a temperature rise deteriorates vehicle performance, and the vehicle may shut down in severe cases, which may cause a significantly dangerous situation to a driver. Therefore, accurately diagnosing a coolant insufficiency in a power converter cooling system and informing the driver to prevent overheating in a control circuit in advance are critical.
A reliable diagnosis of an insufficiency of a coolant control technology through a cooperative control between controllers based on analysis and evaluation of disturbance factors, such as an input voltage, a control duty, a vehicle deviation, a component deviation, a duration of deterioration, a coolant temperature, a coolant amount, an inclined angle sensor error, and the like of the electric water pump (EWP) of the power converter cooling system can be implemented.
A vehicle using an electric water pump (EWP) according to the related art does not have a function of diagnosing an absence or insufficiency of a coolant, but a method of indirectly diagnosing absence or insufficiency of a coolant by calculating a temperature rise rate using a temperature sensor has been mainly used.
For example, a deviation (gradient) of a temperature change depending on time is larger when there is less coolant when a vehicle switch is turned on. The coolant is assumed to be insufficient when the deviation is excessive compared with temperature change modeling measured when the coolant is sufficient. The driver is then informed about the insufficiency of coolant, thereby preventing a problem associated with insufficiency of the coolant.
The matters described in the Background section are provided only to assist in the understanding for the background of the present disclosure and should not be considered as corresponding to the related art known to those skilled in the art.